Module 2: Cervix in Pregnancy Flashcards
what are the three methods to asses the cervix
- transabominal
- transvaginal
- translabial
what is needed for the transabdominal approach to be effective
- partially full bladder
what can happen to the patients cervix if the bladder is too full
- falsely elongate the cervix by compressing the lower uterine segment and making it look like its part of the cervix
what other situation can make a sonogpaher falsely elongate the cervix other than a full bladder
- uterine contractions close to the cervix
when is the translabial approach used
- used when ruptured membranes has occurred
- or with placenta previa
what is the translabial approach limited by
- rectal gas
does the patient need a full bladder with the translabial approach
- no
what method is the gold standard (most accurate) for measuring cervical length
- transvaginal
how far should the EV probe be inserted to measure cervical length
- 3-4cm
when is EV contraindicated to measure cervical length
- when ruptured membranes has occurred
what two things can the EV exam cause for the patient
- bleeding
- contractions
what does the normal cervix look like on ultrasound
- echogenic canal (mucous plug)
- can appear hypoechoic
what is the lower limit of normal for the cervix
30mm
what does a cervix of 15mm correspond too
50% effacement
what does a cervix of 10mm corresponds too
75% effacement
what is funnelling
- herniation of the fetal membranes into the internal os but the external os remains closed
what is funnelling an early sign of
incompetent cervix
- increased risk of preterm delivery
what AP measurement is considered abnormal cervical dilation before 30 weeks
> 5mm
what is cervical incompetence
- dynamic process
- cervix changes spontaneously and dramatically in a short period of time
when does cervical incompetence occur
- cervix is unable to retain a pregnancy to full term
how is cervical incompetence acquired
- laceration of the cervix due to excessive dilation with a D&C
how is cervical incompetence congenitally acquired
- having a misshapen uterus do to DES exposure
what is the classic presentation of cervical incompetent
- painless cervical dilation
- history of recurrent second trimester losses
what is the DDX of cervical incompetence but what is the difference between the two diagnosis
- pre term labour
- patient will be experiencing contractions
- contractions strong enough to change the cervix
- cervix will then dilate
what is the treatment for an incompetent cervix
- cervical cerclage
what is a cervical cerclage
- purse string suture is applied to the cervix
- inserted between 13-16 weeks in patient with a known cervical incompetence
what conditions do patients have an increased chance of getting sue to a cerclage
- amnionitis
- rupture of membranes
what does a cerclage look like on ultrasound
- hyperechoic linear structure with acoustic shadow seen in anterior and posterior cervix
what are three other names for cervical cerclage
- shirodkar suture
- McDonald suture
- transabdominal
